Calculation of inclusion formation in low-alloy-steel welds

Equilibrium thermodynamic calculations were performed to predict the sequential inclusion formation in low-alloy-steel welds. In the calculations the multi-phase equilibrium between oxides and liquid steel was considered. The oxidation sequence was found to be sensitive to small changes in the weld metal composition. The calculations are compared with experimental measurements available in the literature. Calculated aluminum and titanium concentrations in solid solution in the weld correlated well with experimental data. The calculations indicate that the present method can be used as a first approximation to describe the inclusions formation in low-alloy-steel welds. The results are discussed with reference to the acicular ferrite microstructure development.